Geometrical Modelling of 3d Textile Composite Application to Warp Interlock Carbon Fabrics

In order to better predict the composite material behaviour, mechanical engineers need safe software tools to model the textile structure and to integrate into simulating software by the use of finite element approach. Then, it’s necessary to have a clear description of the textile structure at each scale. The microscopic scale involves the filaments position and distribution to define the external shape and mechanical properties of the yarn. The macroscopic scale tends to define the different mechanical interactions between warp and weft yarns at the crossover points. The mesoscopic scale attempts to give the exact position of each yarn paths and shapes inside the woven geometry used linked with the mechanical parameters of yarns and crossover points of the fabric. The global approach of Textile modelling proposed by Lomov et al. [1] is mainly based on these different scales analysis and also taking into account the non linear and non conservative behaviour of yarns in compression and bending. The geometric structure modelling can be clustered into three groups [2]. The continuous structure models have been studied by Steigmann [3] to give filaments formulation, by Reese [4] to integrate anisotropic and elastic formulation, also by Xue et al [5] and Shockey et al [6][7][8][9][10] to describe woven structures. The Meso-structure models have been first introduced by Peirce [11] to give a mathematical geometric formulation of the crossover point, with buckling shapes of yarns for Warren [12], with non circular shape of yarns for Sagar et al [13]. Kawabata [14][15][16] has proposed analytical models of the fabric geometry based on bi-axial tensile and shear behaviours. On the basis of Kawabata model, improvements have been done by Kato et al [17] through trellis geometry, by Realff et al [18] thanks to the compressive properties of yarns, by Boisse et al. [19] and Rattensperger et al. [20] to integrate the bending of yarns and shear general behaviour of the fabric. The numerical structure models help to describe all the fabric buckling mechanisms through a precise description of mechanical parameters acting on yarns Ng et al. [21], Boisse et al. [22]. Among all these geometrical modelling approaches defined in the recent literature, the proposed approach of this paper, described in Fig. 1, tends to capture the real path of yarns and their different shapes inside the textile structure. All these observations help us to statistically define an average distribution of the real yarn with respect to the given parameters of the yarn as the yield, tow count and twist value, and also of the fabric as the number of layers, the warp and weft densities and the weave diagram. Thus, a comparison can be made with the real parameters and the simulated values given by the recent 3D model given by Shang and Shuong [23]. This modelling approach has been applied on a 3D textile structure (known as Angle interlock or warp interlock) made with 3k carbon filaments yarns. The obtained results define more precisely the path and shape of yarns inside the 3D textile structure and thus help the mechanical engineers to have the exact position of yarns for making safe simulations of the composite material behaviour.